Currently there are various methods used in control of pests on large domestic animals such as livestock. Commonly employed methods of pest control include ear tags or tapes, sprays and dusts, and back rubbers and dust bags.
Ear tags or tapes are pesticide-impregnated materials which are attached to animals by piercing the ear with a sharp post and corresponding locking receptacle or with adhesive. The pesticide slowly leaches from the carrier material and is deposited to the animal. The animal will then spread the material by moving its head from side to side and by rubbing alongside other animals.
This method of pesticide application tends to have a diminishing effect through its life cycle as the pesticide level eventually runs low enough that sub-lethal amounts of pesticide are deposited on the animal. This poses a serious problem, as sub-lethal applications of pesticide will allow pests to build a tolerance to the pesticide. Future generations of pests may subsequently become immune to what were once lethal exposures to the pesticide.
Sprays, dusts, and pour-on applications of pesticide involve the manual application of pesticide to the animal's back. Although this method can be effective, it requires additional herding and handling and may not be practical for large ranches or for free-range cattle.
Back rubbers and dust bags impregnated or filled with pesticide and suspended in a pasture in proximity to a salt lick, water supply or place where the animals are known to rest. The animals will make contact with the device in the normal course of their routine. In addition, the dust bag or back rubber may be located in a gateway which leads to a salt lick or water supply and which forces the animal to contact the device. Again, this method of insecticide application can be effective, but may not be practical for certain situations such as large ranches or free-range cattle.
It would be desirable to have an application method and dispenser that is capable of dosing a repeatable, prolonged, and lethal application of pesticide to an animal with no gradual decline, but rather, a sudden and complete cessation of exposure, and does not require further herding, handling or contact with the animal.